Multi-radio wireless mesh network solutions

ABSTRACT

Techniques for providing multi-radio wireless mesh network solutions are described herein. According to one embodiment, routing information of neighboring mesh APs is monitored via a dedicated monitoring antenna of a current mesh access point (AP). The current mesh AP is one of mesh APs of a wireless mesh network, each having an uplink antenna, a downlink antenna, a local link antenna, and a monitoring antenna. Traffic of an uplink antenna of the wireless mesh AP is dynamically reconfigured and rerouted from a first routing path coupled to a first uplink mesh AP to a second routing path coupled to a second uplink mesh AP, if the second routing path has a better routing condition than the first routing path based on the monitored routing information associated with the first uplink mesh AP and the second uplink mesh AP. Other methods and apparatuses are also described.

RELATED APPLICATION

This application claims the priority of U.S. Provisional PatentApplication No. 61/055,107, filed May 21, 2008. This application is alsoa continuation-in-part (CIP) of co-pending U.S. patent application Ser.No. 12/124,961, filed May 21, 2008, which claims priority from U.S.Provisional Patent Application No. 60/939,314, filed May 21, 2007. Thisapplication is also a continuation-in-part (CIP) of co-pending U.S.patent application Ser. No. 12/124,965, filed May 21, 2008. Thedisclosure of the above-identified applications is incorporated byreference herein in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to wireless networks. Moreparticularly, this invention relates to multi-radio wireless meshnetwork solutions.

BACKGROUND

Wireless mesh networks are gaining popularity because wirelessinfrastructures are typically easier and less expensive to deploy thanwired networks. The wireless mesh networks typically include wiredgateways that are wirelessly connected to wireless nodes, or wirelessconnected directly to client devices. Many wireless nodes cancollectively provide a wireless mesh, in which client devices canassociate with any of the wireless nodes.

Typically, the wireless nodes are implemented as wireless access points(APs). A typical wireless AP includes a local link interface tocommunicate with local client devices and a downlink and uplinkinterfaces to communicate with other APs. Conventional APs utilize thesame communication frequency when communicating with other APs. As aresult, there may be an interference between an uplink and a downlinkcommunications and may have impact on the signal quality. In addition,communications between the wireless APs typically are in a form of plaintext which may be vulnerable to be attacked.

SUMMARY OF THE DESCRIPTION

Techniques for providing multi-radio wireless mesh network solutions aredescribed herein. According to one embodiment, routing information ofneighboring mesh APs is monitored by monitoring logic via a dedicatedmonitoring antenna of a current mesh access point (AP). The current meshAP is one of mesh APs of a wireless mesh network. Each of the mesh APsincludes an uplink antenna to communicate with an uplink mesh AP, adownlink antenna to communicate with a downlink mesh AP, a local linkantenna to communicate with a local client of each mesh AP, and amonitoring antenna for monitoring neighboring mesh APs. Traffic of anuplink antenna of the wireless mesh AP is dynamically reconfigured andrerouted from a first routing path coupled to a first uplink mesh AP toa second routing path coupled to a second uplink mesh AP, if the secondrouting path has a better routing condition than the first routing pathbased on the monitored routing information associated with the firstuplink mesh AP and the second uplink mesh AP obtained via the dedicatedmonitoring antenna of the mesh AP.

Other features of the present invention will be apparent from theaccompanying drawings and from the detailed description which follows.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and notlimitation in the figures of the accompanying drawings in which likereferences indicate similar elements.

FIG. 1 is a block diagram illustrating an example of a wireless meshnetwork configuration which may be used with an embodiment of theinvention.

FIG. 2 is a block diagram illustrating inter-mesh AP communicationsaccording to one embodiment of the invention.

FIG. 3 is a block diagram illustrating an example of a wireless meshaccess point according to one embodiment of the invention.

FIG. 4 is a block diagram illustrating an example of softwarearchitecture of a wireless mesh access point according to one embodimentof the invention.

FIG. 5 is a block diagram illustrating a data structure representing arouting table according to one embodiment of the invention.

FIG. 6 is a block diagram illustrating a data structure representing aninterface mapping table according to one embodiment of the invention.

FIG. 7 is a block diagram illustrating a data packet used for tunnelingaccording to one embodiment of the invention.

FIG. 8 is a flow diagram illustrating a process for routing a packet ina wireless mesh network according to one embodiment of the invention.

FIG. 9 is a flow diagram illustrating a process for routing a packet ina wireless mesh network according to another embodiment of theinvention.

FIG. 10 is a block diagram illustrating a mesh network configurationaccording to another embodiment of the invention.

FIG. 11 is a block diagram illustrating an example of a wireless meshaccess point according to another embodiment of the invention.

FIG. 12 is a flow diagram illustrating a method performed by a mesh APaccording to one embodiment of the invention.

FIG. 13 illustrates a diagrammatic representation of a machine in theexemplary form of a computer system.

DETAILED DESCRIPTION

Techniques for providing multi-radio wireless mesh network solutions aredescribed herein. In the following description, numerous details are setforth to provide a more thorough explanation of embodiments of thepresent invention. It will be apparent, however, to one skilled in theart, that embodiments of the present invention may be practiced withoutthese specific details. In other instances, well-known structures anddevices are shown in block diagram form, rather than in detail, in orderto avoid obscuring embodiments of the present invention.

Reference in the specification to “one embodiment” or “an embodiment”means that a particular feature, structure, or characteristic describedin connection with the embodiment is included in at least one embodimentof the invention. The appearances of the phrase “in one embodiment” invarious places in the specification do not necessarily all refer to thesame embodiment.

According certain embodiments of the invention, multiple wireless pathdesign is provided for both backhaul (e.g., also referred to as a meshlink among multiple mesh APs) and user traffic (e.g., also referred toas a client link between an AP and a local end-user client) to eliminateadjacent AP signal interference degradation. There has been provided abest network throughput via layer 2 fast switching and bridging from AP(access point) to AP to support real time video, voice, and dataapplications. It is fully compatible with existing access servers,routers, and gateways since existing drivers and layer 3 applicationsare not modified. It is transparent to layer 3 and up protocols andthus, it is fully compatible with existing network infrastructure orequipments. An AP is directly connected to existing routers, gateways,or AP through, for example, 10/100 Ethernet. The management and securitysoftware architecture is configured to support Web based browser andSNMP (simple network management protocol). It also supports WEP(wireless encryption protocol) encryption security across wireless meshnetwork. Multiple APs can be coupled to each other based on a mesh IDassigned by a user or administrator.

In one embodiment, each node includes multiple wireless interfaces orantennas. For example, a node in a mesh network may include a local APantenna that operates as an AP for local clients (e.g., end-user clientssuch as laptop computers, etc.) In addition, the node may furtherinclude multiple mesh link AP antennas, one for uplink and one for downlink. An uplink interface is configured to communicate with a downlinkinterface of another node and likewise, a downlink interface of a nodeis configured to communicate with an uplink interface of another node.Separate channels (e.g., different communication frequencies) are usedfor uplink and downlink. As result, air link interference can be greatlyreduced.

According to another embodiment of the invention, software architectureutilizes existing wireless architecture such as IEEE 802.11 WiFi clientand AP drivers, to achieve WIFi mesh network design. As a result, thesystem can maintain most of the features of WiFi client driver and WiFiaccess point driver so that it is fully compatible with certain thirdparty products while creating a mesh WiFi network. For example, thesoftware architecture includes an additional layer (also referred toherein as layer 2.5) between ordinary layer 2 and layer 3 of a networkstack to process data received from layer 2 driver before delivering thedata to ordinary layer 3 or alternatively, sending the data back down tolayer 2 without sending the data to layer 3, dependent upon specificsystem design. As a result, third party layers 2 and 3 can be utilizedwithout having to modify a specific driver of a third party vendors.

Further, according to a further embodiment, tunneling is designed totransfer data packets from one node to another node going throughstandard WiFi client and AP design. For example, each node includes acommon AP interface to communicate with multiple clients, where eachclient communicates with the node via a tunneling technique using thecommon AP interface. Thus, when a node receive a data packet from aclient via normal WiFi client/AP communication protocol, the specificdata associated with the sender is encrypted using a variety of dataencryption techniques and tunneled within the standard WiFi packets. Thereceiving node then may decrypt the data packets to reveal who is theactual sender. Further, each node that communicates with the APinterface of a particular node may appear as a virtual node in theparticular node.

According to a further embodiment, each node in a WiFi mesh networkincludes a routing module (also referring to as a bridging module) and adatabase. The database is used to store information of other nodes whichmay be collected (e.g., learned) during communications with other nodesincluding, for example, signal strength, MAC (media access control)addresses, link status, and mesh links (e.g., parent and/or childnodes). The information stored in the database may be used to determinethe best route to route the data packets. For example, each node may beassigned with a mesh ID by a user or an administrator. Under certaincircumstances, only those nodes having the identical mesh ID may begrouped in a mesh network. Further, the signal strength information maybe used to identify the adjacent nodes in the mesh network to determinethe shortest route to an AP.

According another embodiment, if a first node has too many hop counts toa master node, and a second node has less hop counts, the first andsecond nodes may communicate with each other to “relocate” certainroutes from the first node to the second node for the load balancingpurposes.

In one embodiment, each AP includes a dedicated wireless interface orantenna to actively monitor operations such as routing information ofneighboring APs in order to determine an optimum route for itsassociated uplink path, downlink path, and local link path. That is,each AP includes at least four wireless interfaces or antennas: 1)uplink interface; 2) downlink interface; 3) lock link interface; and 4)monitoring interface. The monitoring logic within an AP activelymonitors via the corresponding dedicated wireless interface all meshlinks associated with the corresponding AP. If a better routing path isavailable, the traffic may be rerouted to the better routing path forthe corresponding uplink, downlink, and/or local link of the respectiveAP to optimize the mesh network quality.

FIG. 1 is a block diagram illustrating an example of a wireless meshnetwork configuration which may be used with an embodiment of theinvention. Referring to FIG. 1, wireless mesh network configuration 100includes, but is not limited to, multiple mesh APs 103-106communicatively coupled to each other as depicted via dash communicationlinks. Some of the APs such as APs 103-104 may be coupled via a wirednetwork to a gateway device 102 which allows traffic from the wirelessmesh network to reach an external network or another network 101 such aswide area network (WAN), which may be the Internet.

Each of the APs 103-106 includes a local AP link to communicate withlocal clients (e.g., end-user clients) 107-114. Each of the clients107-114 may be associated with any of the APs 103-106, which may bestatically assigned by an administrator or alternatively, via roamingdynamically. In this example, clients 107-108 are associated with AP103; clients 109-110 are associated with AP 105, clients 111-112 areassociated with AP 106; and clients 113-114 are associated with AP 104respectively.

According to one embodiment, each of the APs 103-106 includes an uplinkinterface or antenna and a downlink interface or antenna. An uplinkinterface of one AP is used to communicate with a downlink interface ofanother AP. Similarly, a downlink interface of one AP is used tocommunicate with an uplink interface of another AP. For example, an uplink interface of AP 105 may be used to communicate with a downlinkinterface of AP 103. Likewise, a downlink interface of AP 105 may beused to communicate with an uplink interface of AP 106.

According to one embodiment, communication frequencies for the uplinkinterface and downlink interface of a particular AP may be differentwhich may be selected or configured by an administrator statically ordynamically (e.g., auto discovery or via frequency hopping). In thisway, each backhaul communication link between two APs may have differentfrequency which greatly reduces the interference.

Furthermore, according to another embodiment, data between two APs maybe securely communicated via a tunneling technique. For example, when anAP receives a packet from a local end-user client, the AP may tunnel thepacket by encrypting at least the source and destination MAC (mediaaccess control) addresses as well as the payload of the packet into apayload of a new packet. The new packet is then package with a new setof source and destination MAC addresses, where the new source MACaddress is associated with the AP itself while the destination MACaddress is associated with another AP (e.g., next hop). As a result, thenew packet can be layer-2 routed to the next AP identified by the newdestination MAC address.

When the next hop AP receives the tunneled packet, the next hop APstrips out or removes the source and destination MAC addresses anddecrypt the payload of the tunneled packet to reveal the original packetfrom the end user client. The next hop AP then examines the originaldestination MAC address to determine whether the destination end-userclient is a local end-user client of the next hop AP. If the destinationend-user client is a local end-user client, the original packet istransmitted to the identified local end-user client. If the destinationend-user client is not a local end-user client, the AP then repackagesor re-tunnels the original packet and sends the tunneled packet toanother next hop AP, and so on.

In addition, according to one embodiment, at least one AP includes adedicated wireless interface or antenna to actively monitor operationssuch as routing information of neighboring APs in order to determine anoptimum route for its associated uplink path, downlink path, and locallink path. That is, at least one AP includes at least four wirelessinterfaces or antennas: 1) uplink interface; 2) downlink interface; 3)lock link interface; and 4) monitoring interface. The monitoring logicwithin an AP actively monitors via the corresponding dedicated wirelessinterface all mesh links associated with the corresponding AP. If abetter routing path is available, the traffic may be rerouted to thebetter routing path for the corresponding uplink, downlink, and/or locallink of the respective AP to optimize the mesh network quality. Otherconfigurations may exist.

FIG. 2 is a block diagram illustrating inter-mesh AP communicationsaccording to one embodiment of the invention. For example, APs 201-202may be implemented as any of APs 103-106 of FIG. 1. Referring to FIG. 2,AP 201 includes an uplink interface 203 and a downlink interface 204, aswell as a local link interface 205 for local clients 211. Similarly, AP202 includes an uplink interface 207, a downlink interface 206, and alocal link interface 208 for local clients 212. Downlink interface 204of AP 201 is used to communicate with an uplink interface of a next hop209. Uplink interface 207 of AP 202 is used to communicate with adownlink interface of a next hop 210. Uplink interface 203 is used tocommunicate with a downlink interface 206 of AP 202.

Typically, a local link interface communicates with a local client usinga communication frequency of approximately 2.4 GHz using a standardwireless protocol such as, for example, IEEE 802.11b/g protocol. Thecommunication frequency of the backhaul or mesh link communications isranging approximately from 4.9 to 5.8 GHz using a standard wirelessprotocol such as, for example, IEEE 802.11a protocol. However, accordingto one embodiment, each mesh link may operate at a differentcommunication frequency. For example, with respect to a particular AP,the communication frequency of a downlink interface is different thanthe communication frequency of an uplink interface. As a result, airinterference is greatly reduced.

Furthermore, the communications between downlink interface 206 of AP 202and uplink interface 203 of AP 201 are securely performed using atunneling protocol and/or a variety of encryption techniques. Forexample, when AP 201 receives a packet form a local client 211, the AP201 encrypts almost the entire packet to generate a new packet having asource MAC address of AP 201 and a destination MAC address of AP 202.The new packet is then routed from AP 201 to AP 202 via uplink interface203 of AP 201 and downlink interface 206 of AP 202.

When AP 202 receives the new packet, AP 202 strips out the header (e.g.,source and destination MAC addresses) and decrypts the payload of thenew packet to reveal the original packet originated from end user client211. Based on the destination MAC address of the revealed originalpacket, AP 202 determines whether the original packet is destined to alocal end-user client such as client 212. If the original packet isdestined to a local end-user client, AP 202 then routes the originalpacket to the local client via local link interface 208. However, if theoriginal packet is not destined to a local end-user client, AP 202 mayrepackage or re-tunnel the original packet with a source MAC address ofAP 202 and a destination MAC address of a next hop, which may be an APcommunicatively coupled via uplink interface 207 or another APcommunicatively coupled via downlink interface 206.

FIG. 3 is a block diagram illustrating an example of a wireless meshaccess point according to one embodiment of the invention. For example,AP 300 may be implemented as part of AP 201 or AP 202 of FIG. 2.Referring to FIG. 3, in one embodiment, AP 300 includes, but is notlimited to multiple wireless interface devices 301-303, also referred toherein as RF (radio frequency) or radio cards or devices, each having acorresponding wireless controller and necessary RF circuit,communicatively coupled to each other via bus or interconnect 307. Theradio cards 301-303 may be provided by a third party vendor which alsoprovides a software driver (e.g., layer 2 to layer 7 network driver). Inthis example, AP 300 includes an uplink interface card 301 that can beused to communicate with a downlink interface of another AP. AP 300further includes a downlink interface card 302 that can be used tocommunicate with an uplink interface of another AP and a local linkinterface card 303 used to communicate with a local client.

AP 300 further includes one or more processors 305 coupled to the bus307. In addition, AP 300 further includes a management interface 308 toallow a management station 309 to communicate with AP 300 over a network310 for management purposes. The routing software (not shown) may beloaded within memory 306 and executed by processor 305. For example,each of the interface cards 301-304 may be configured by the managementstation 309 over network 310 to operate in a particular but differentfrequency to reduce air interference, etc. Each interface card may beassigned with a unique interface identifier (I/F ID) that uniquelyidentifies the corresponding interface, physically or logically (e.g.,virtual). Other configurations may exist.

FIG. 4 is a block diagram illustrating an example of softwarearchitecture of a wireless mesh access point according to one embodimentof the invention. For example, software stack 400 may be running withinmemory 306 by processor 305 of FIG. 3. Referring to FIG. 4, softwarestack 400 includes, but is not limited to, layer 3 and up network stack402 and layer 2 404 that can process data exchanged with hardware suchas radio cards 405. Radio cards 405 may be implemented as any of theradio cards 301-304 as shown in FIG. 3. Note that layer 404 and layer402 may be provided with the hardware 405 from a third party vendor.

In addition, according to one embodiment, software stack 400 furtherincludes layer 403, also referred to as layer 2.5 logically representingan additional layer between layer 2 and layer 3 of OSI (open systeminterconnection). Layer 403 includes a routing logic 406 for routingdata received from different radio cards via layer 404. Any data formanagement application such as SNMP (simple network management protocol)application 401 is routed via layer 402. In this embodiment, since layer403 is inserted between layer 404 and 402, the ordinary layer 2 andlayer 3 do not need to modify as layer 403 is completely transparent tolayers 404 and 402.

The data is routed among multiple interfaces (e.g., uplink, downlink, orlocal link) based on information obtained from routing table 408 and/orinterface mapping table 407. Interface mapping table 407 may beimplemented in a manner similar to one as shown in FIG. 5. Likewise,routing table 408 may be implemented similar to one shown in FIG. 6.

Referring to FIG. 5, interface mapping table 500 includes multipleentries. Each entry includes an interface ID field 501, a source MACaddress field 502, and a destination MAC address field 503. Theinterface ID field 501 is used to store an ID of a particular interfaceof the AP. The source MAC address field 502 is used to store a MACaddress corresponding to an interface card (e.g., either uplink ordownlink) identified by the interface ID stored in the interface IDfield 501. The destination MAC address field 503 is used to store a MACaddress of an interface card (e.g., either uplink or downlink) of a nexthop AP device. The interface mapping table is used by the routing logicto tunnel a packet to a next hop.

Referring to FIG. 6, a routing table 600 includes multiple entries. Eachentry includes a MAC address field 601 to store a particular MAC address(e.g., source or destination MAC address) and an interface ID field 602to store an interface ID corresponding to a MAC address stored in MACaddress field 601. This table is used to determine which interface cardthat a particular packet should be sent.

FIG. 7 is a block diagram illustrating a data packet used for tunnelingaccording to one embodiment of the invention. Referring to FIG. 7, inthis example, packet 701 is originally initiated from an end-user clientsuch as client 211 of FIG. 2. In this example, like a standard TCP/IPpacket, packet 701 includes, among others, a source MAC address 703, adestination MAC address, other layer-3 and up header 705, and payload706.

Referring to FIGS. 2 and 7, when AP 201 receives packet 701 where AP isconfigured to maintain its own copy of interface mapping table (e.g.,table 500 of FIG. 5) and a routing table (e.g., table 600 of FIG. 6), AP201 may perform a lookup operation at the routing table to determinewhether a source MAC address 703 (e.g., MAC address representing theend-user client 211) exists in the routing table. If not, AP 201 maystore or insert a new entry into the routing table having the source MACaddress 703 and an interface ID corresponding to an incoming interfaceof AP 201, in this example, interface 205.

In addition, according to one embodiment, AP 201 may further performanother lookup operation at the routing table based on the destinationMAC address 704. It is assumed that an administrator initially hasconfigured all the necessary routing paths in the mesh network. Thus,there should be an entry in the routing table having a MAC addresscorresponding to destination MAC address 704 associated with aparticular interface (e.g., outgoing or egress interface) in the routingtable. From the routing table, based on the destination MAC address 704,an outgoing interface ID is obtained that corresponds to, in thisexample, interface 203.

Further, according to one embodiment, AP 201 may further perform anotherlookup operation at the interface mapping table based on the interfaceID obtained from the routing table to determine a pair of source MACaddress 708 and destination MAC address 709, where the source MACaddress 708 represents a MAC address associated with the outgoinginterface of current AP and the destination MAC address 709 representsan ingress interface of a next hop AP. As a result, a new packet 702 isgenerated having source MAC address 708 and destination MAC address 709,where most of the original packet 701 having fields 703-706 is encrypted(e.g., tunneled) using a variety of encryption methods to generate a newpayload 707 of pocket 702. Packet 702 is then transmitted to a next hopAP 202 via interface 203.

When AP 202 receives packet 702, AP 202 strips off the header having atleast source MAC address 708 and destination MAC address 709 anddecrypts payload 707 to reveal the original packet 701. Again, similarto operations performed by AP 201, AP 202 determines whether therevealed packet 701 is intended for its local end-user client such asclient 212. If so, the revealed packet 701 is then transmitted to thelocal client. Otherwise, the packet 701 is then repackaged and tunneledto another AP using techniques similar to those set forth above. As aresult, communications between two AP local networks can be securelyperformed.

Note that packets 701-702 are shown for purposes of illustration only.Other formats may also be applied. For example, instead of wrapping theoriginal MAC addresses of the packet 701 using the AP MAC addresses togenerate packet 702, the original MAC addresses of packet 701 may bereplaced by the AP MAC addresses. The original MAC addresses may berelocated to some other locations such as the end of packet 702.

FIG. 8 is a flow diagram illustrating a process for routing a packet ina wireless mesh network according to one embodiment of the invention.Note that process 800 may be performed by processing logic which mayinclude hardware, software, or a combination of both. For example,process 800 may be performed by a wireless mesh AP such as AP 300 ofFIG. 3. Referring to FIG. 8, at block 801, a first packet (e.g., packet701 of FIG. 7) is received via an incoming or ingress interface (e.g.,local link interface) from a local end-user client having a source MACaddress representing the local end-user client and a destination MACaddress representing a destination end-user client.

At block 802, an outgoing or egress interface (e.g., interface ID) isdetermined based on the destination MAC address of the first packet. Forexample, the egress interface ID may be determined via a lookupoperation of a routing table maintained within the respective AP (e.g.,routing table 600 of FIG. 6). At block 803, if the source MAC address ofthe first packet does not exist in the routing table, a new entry iscreated in the routing table for storing the source MAC address and aninterface ID corresponding to an interface from which the first packetis received.

At block 804, based on the egress interface ID determined above, an APsource MAC address and an AP destination MAC address are determined. Forexample, the AP source and destination MAC addresses may be determinedvia a lookup operation on the interface mapping table maintained withinthe respective AP (e.g., table 500 of FIG. 5). At block 805, a newpacket or a second packet (e.g., packet 702 of FIG. 7) is created usingthe AP source and destination MAC address by tunneling the first packet,including encrypting at least the source and destination MAC addressesas well as the payload of the first packet. Thereafter, at block 806 thenew packet is transmitted to a proper interface identified by theinterface ID, which is then routed to a next hop AP.

FIG. 9 is a flow diagram illustrating a process for routing a packet ina wireless mesh network according to another embodiment of theinvention. Note that process 900 may be performed by processing logicwhich may include hardware, software, or a combination of both. Forexample, process 900 may be performed by a wireless mesh AP such as AP300 of FIG. 3. Referring to FIG. 9, at block 901, a first packet isreceived via an incoming or ingress interface from a previous hop AP,the first packet having a first source MAC address and a firstdestination MAC address, as well as a payload. The first source MACaddress is associated with an egress interface of the previous hop APand the destination MAC address is associated with an ingress interfaceof the current hop AP. Note that the ingress interface of the currenthop AP may be an uplink interface or a downlink interface. Similarly, anegress interface of a previous hop AP may be an uplink interface or adownlink interface.

At block 902, the source and destination MAC addresses of the firstpacket is stripped off and the payload is decrypted to reveal a secondpacket that has been tunneled within the first packet. The second packetincludes a second source MAC address associated with a first end-userclient (e.g., original end-user client that initiates the first packetform a local link) and a destination MAC address associated with asecond end-user client as a destination end-user client intended toreceive the first packet.

At block 903, it is determined whether the second packet is intended toa local end-user client of a current hop AP (e.g., whether the secondend-user client is a local end-user client). For example, a lookupoperation may be performed at a routing table maintained by the currenthop AP based on the destination MAC address of the second packet (e.g.,whether an interface ID corresponding to the destination MAC address ofthe second packet represents a local link interface of a current hopAP). If the second packet is intended to a local end-user client of acurrent hop AP, at block 904, the second packet is transmitted to theintended local end-user client via a local link interface of the currenthop AP.

If the second packet is not intended to a local end-user client of acurrent hop AP, at block 905, the second packet is then tunneled withina third packet, and the third packet is then transmitted to a next hopAP using techniques similar to those set forth above. Other operationsmay also be performed.

FIG. 10 is a block diagram illustrating a mesh network configurationaccording to another embodiment of the invention. For example, networkconfiguration 250 may be implemented as part of those as shown in FIGS.1-2. Note that for the purpose of illustration, certain referencenumbers for the components having similar functionality are maintainedthe same. Referring to FIG. 10, similar to network configuration 200 ofFIG. 2, AP 201 includes an uplink interface 203 and a downlink interface204, as well as a local link interface 205 for local clients 211.Similarly, AP 202 includes an uplink interface 207, a downlink interface206, and a local link interface 208 for local clients 212. Downlinkinterface 204 of AP 201 is used to communicate with an uplink interfaceof a next hop 209. Uplink interface 207 of AP 202 is used to communicatewith a downlink interface of a next hop 210. Uplink interface 203 isused to communicate with a downlink interface 206 of AP 202.

Typically, a local link interface communicates with a local client usinga communication frequency of approximately 2.4 GHz using a standardwireless protocol such as, for example, IEEE 802.11b/g protocol. Thecommunication frequency of the backhaul or mesh link communications isranging approximately from 4.9 to 5.8 GHz using a standard wirelessprotocol such as, for example, IEEE 802.11a protocol. However, accordingto one embodiment, each mesh link may operate at a differentcommunication frequency. For example, with respect to a particular AP,the communication frequency of a downlink interface is different thanthe communication frequency of an uplink interface. As a result, airinterference is greatly reduced.

Furthermore, the communications between downlink interface 206 of AP 202and uplink interface 203 of AP 201 are securely performed using atunneling protocol and/or a variety of encryption techniques. Forexample, when AP 201 receives a packet form a local client 211, the AP201 encrypts almost the entire packet to generate a new packet having asource MAC address of AP 201 and a destination MAC address of AP 202.The new packet is then routed from AP 201 to AP 202 via uplink interface203 of AP 201 and downlink interface 206 of AP 202.

When AP 202 receives the new packet, AP 202 strips out the header (e.g.,source and destination MAC addresses) and decrypts the payload of thenew packet to reveal the original packet originated from end user client211. Based on the destination MAC address of the revealed originalpacket, AP 202 determines whether the original packet is destined to alocal end-user client such as client 212. If the original packet isdestined to a local end-user client, AP 202 then routes the originalpacket to the local client via local link interface 208. However, if theoriginal packet is not destined to a local end-user client, AP 202 mayrepackage or re-tunnel the original packet with a source MAC address ofAP 202 and a destination MAC address of a next hop, which may be an APcommunicatively coupled via uplink interface 207 or another APcommunicatively coupled via downlink interface 206.

In addition, in one embodiment, each mesh AP includes a monitoringinterface (e.g., a separate wireless antenna) for monitoring purposes.For example, AP 202 includes monitoring interface 214 and AP 201includes monitoring interface 213. In one embodiment, each AP includes amonitoring or scan logic (not shown) configured to monitor or scan viaits associated monitoring interface or antenna neighboring routinginformation and to decide whether there is a need to reroute networktraffic through a better routing path. A better path may be identifiedbased on various information obtained by the monitoring logic fromneighboring APs, such as, for example, based on signal strength, hopcount, and a number of downlink stations, etc. A path having a shorterhop count, a stronger signal to noise ratio (SNR), and less number ofdownlink stations associated it may be a better path. Such informationmay be received as part of a beacon signal broadcast by each AP.

For example, with respect to AP 201, when the monitoring logic monitorsand detects via monitoring interface 213 that a path via AP 215 is abetter path than an existing path via AP 202, the management logic (notshown) of AP 201 may reconfigure uplink interface 203 to be associatedwith a downlink of AP 215, rather than the downlink of AP 202.

Further, according to one embodiment, the monitoring logic of each APmay monitor environment and to change channel assignment of the downlinkchannels and local link channels. The channel reassignment may beperformed during and/or after routing of traffic. For example, ifcongestion of a particular channel of a downlink radio and/or local linkradio reaches certain threshold, a new channel reassignment for thedownlink and local link is performed. The congestion may be determinedbased on variety of parameters such as overall SNR of each AP and thenumber of APs currently associated with a particular channel, etc.Typically, stronger SNR of a particular channel may suggest higherprobability of conflict or interference. Similarly, a channel having ahigher number of downlink APs may suggest certain degrees of trafficcongestion. Note that the monitoring and configuration techniques may beperformed by logic (e.g., implemented in software, hardware, or both)automatically according to certain programmable algorithms that may bestored in a machine readable storage medium (e.g., memory or storagedevice) of the corresponding AP.

Furthermore, the monitoring logic and interface may also be used forsecurity purposes. According to one embodiment, the monitoring logic viaits monitoring antenna may monitor other surrounding APs and todetermine whether a particular AP is a rogue AP (e.g., an unauthorizedor non-authenticated device). In one embodiment, the monitoring logic ofan AP may send a specific message to another AP and examine the responsefrom the recipient. Based on the response (or non-response), themonitoring logic determines whether the recipient is a rogue AP. Here,given a specific message, the monitoring logic expects a specific reply.If the reply does not include a signature that matches a predeterminedpattern, the recipient AP may be considered as a rogue AP.Alternatively, the monitoring logic may access or log into another AP toexamine a particular key component (e.g., chip ID) to determine whetherthat AP is a rogue AP. If it is determined that a particular AP is arogue AP, a message may be sent to a management system for securitypurposes. Other configurations may exist.

FIG. 11 is a block diagram illustrating an example of a wireless meshaccess point according to another embodiment of the invention. Forexample, AP 350 may be implemented as part of AP 201 or AP 202 of FIG.2. Referring to FIG. 11, similar to the one as shown in FIG. 3, in oneembodiment, AP 350 includes, but is not limited to multiple wirelessinterface devices 301-304, also referred to herein as RF (radiofrequency) or radio cards or devices, each having a correspondingwireless controller and necessary RF circuit, communicatively coupled toeach other via bus or interconnect 307. The radio cards 301-304 may beprovided by a third party vendor which also provides a software driver(e.g., layer 2 to layer 7 network driver). In this example, AP 350includes an uplink interface card 301 that can be used to communicatewith a downlink interface of another AP. AP 350 further includes adownlink interface card 302 that can be used to communicate with anuplink interface of another AP and a local link interface card 303 usedto communicate with a local client.

AP 350 further includes one or more processors 305 coupled to the bus307. In addition, AP 350 further includes a management interface 308 toallow a management station 309 to communicate with AP 350 over a network310 for management purposes. The routing software (not shown) may beloaded within memory 306 and executed by processor 305. For example,each of the interface cards 301-304 may be configured by the managementstation 309 over network 310 to operate in a particular but differentfrequency to reduce air interference, etc. Each interface card may beassigned with a unique interface identifier (I/F ID) that uniquelyidentifies the corresponding interface, physically or logically (e.g.,virtual). Other configurations may exist.

Furthermore, AP 350 includes a monitoring interface card 304 used tomonitor or survey the mesh networks which may be used to reassign orbalance the APs in the network such that the devices in the network canoptimally operate. For example, monitoring interface card 304 mayinclude monitoring logic for monitoring purposes using certaintechniques described above.

As described above, each AP may actively monitor using the correspondingmonitoring logic and monitoring antenna mesh links of the mesh network.If a better mesh link path is available, its uplink interface may bereconfigured to be associated with the better mesh link or path.Similarly, if a better channel is available, its downlink and/or locallink may be reassigned with another channel. The monitoring features mayalso be utilized for fault tolerance purpose. For example, if a managingnode is down and detected by a monitoring logic of an AP, the AP maynotify and cause other APs to switch to another managing node of themesh network. Once the down managing node is up and running, themonitoring logic may detect that and cause the traffic to be reroutedback to the resumed managing node. It can also be applied to redundancypurposes, where when one manager node down, all nodes will beautomatically connected to next available manager node to maintainservices.

This monitoring feature can be used to implement an “always connect”feature of the mesh network. Such a feature forces a mesh AP node to beassociated with another node having a lower SNR if the mesh AP node doesnot have any other better node to establish a mesh link. The monitoringfeature may also be applied to determining bandwidth scores of each meshlink, for example, based on hop count, signal quality, and mesh managerweight, etc., which may be collected through the monitoring logic andits associated monitoring interface. The bandwidth scores may affect therouting decision of each node on the mesh network. For example, morenodes may be associated with a manager node having a higher bandwidthscore. Other areas may also be applied herein.

FIG. 12 is a flow diagram illustrating a method performed by a mesh APaccording to one embodiment of the invention. Note that method 1200 maybe performed by processing logic which may include software, hardware,or a combination of both. For example, method 1200 may be performed byany AP as described above. Referring to FIG. 12, at block 1201,processing logic monitors via a dedicated wireless interface (e.g.,dedicated monitoring antenna) routing information (e.g., strength, hopcount, number of downlink APs, etc.) of neighboring APs. Based on themonitored information, if there is a better path, at block 1202, theuplink traffic is rerouted to the better path (e.g., from one AP toanother AP coupled to the uplink interface). At block 1203, processinglogic monitors traffic congestion conditions (e.g., SNR, number of APsper channel, etc.) of downlink interface and/or local link interface. Ifthere is a traffic congestion based on the monitored traffic congestionconditions, at block 1204, a new channel may be assigned to the downlinkand/or local link. At block 1205, processing logic transmits via thededicated monitoring antenna a specific message or packet to another APrequesting that AP to identify itself in an attempt to determine whetherthat AP is a rogue AP. Based on the response from the suspect AP, atblock 1206, the management system is alerted if the response does notmatch a predetermined signature, which indicates that the suspect AP isa rogue AP. Other operations may also be applied.

FIG. 13 illustrates a diagrammatic representation of a machine in theexemplary form of a computer system within which a set of instructions,for causing the machine to perform any one or more of the methodologiesdiscussed herein, may be executed. In alternative embodiments, themachine may be connected (e.g., networked) to other machines in a LocalArea Network (LAN), an intranet, an extranet, or the Internet. Themachine may operate in the capacity of a server or a client machine in aclient-server network environment, or as a peer machine in apeer-to-peer (or distributed) network environment. The machine may be apersonal computer (PC), a tablet PC, a set-top box (STB), a PersonalDigital Assistant (PDA), a cellular telephone, a web appliance, aserver, a network router, switch or bridge, or any machine capable ofexecuting a set of instructions (sequential or otherwise) that specifyactions to be taken by that machine. Further, while only a singlemachine is illustrated, the term “machine” shall also be taken toinclude any collection of machines (e.g., computers) that individuallyor jointly execute a set (or multiple sets) of instructions to performany one or more of the methodologies discussed herein.

The system 1000 may be used as a client, a server, a gateway device, ora wireless mesh access point described above. For example, system 1000may be implemented as part of any of gateway 102, clients 107-114, orAPs 103-106 of FIG. 1 or alternatively, management system 309 of FIG. 3.System 1000 may also be implemented as part of any AP described above.

As shown in FIG. 13, the system 1000, which is a form of a dataprocessing system, includes a bus or interconnect 1002 which is coupledto one or more microprocessors 1003 and a ROM 1007, a volatile RAM 1005,and a non-volatile memory 1006. The microprocessor 1003 is coupled tocache memory 1004 as shown in the example of FIG. 13. Processor 1003 maybe, for example, a PowerPC microprocessor or an Intel compatibleprocessor. Alternatively, processor 1003 may be a digital signalprocessor or processing unit of any type of architecture, such as anASIC (Application-Specific Integrated Circuit), a CISC (ComplexInstruction Set Computing), RISC (Reduced Instruction Set Computing),VLIW (Very Long Instruction Word), or hybrid architecture, although anyappropriate processor may be used.

The bus 1002 interconnects these various components together and alsointerconnects these components 1003, 1007, 1005, and 1006 to a displaycontroller and display device 1008, as well as to input/output (I/O)devices 1010, which may be mice, keyboards, modems, network interfaces,printers, and other devices which are well-known in the art.

Typically, the input/output devices 1010 are coupled to the systemthrough input/output controllers 1009. The volatile RAM 1005 istypically implemented as dynamic RAM (DRAM) which requires powercontinuously in order to refresh or maintain the data in the memory. Thenon-volatile memory 1006 is typically a magnetic hard drive, a magneticoptical drive, an optical drive, or a DVD RAM or other type of memorysystem which maintains data even after power is removed from the system.Typically, the non-volatile memory will also be a random access memory,although this is not required.

While FIG. 13 shows that the non-volatile memory is a local devicecoupled directly to the rest of the components in the data processingsystem, embodiments of the present invention may utilize a non-volatilememory which is remote from the system; such as, a network storagedevice which is coupled to the data processing system through a networkinterface such as a modem or Ethernet interface. The bus 1002 mayinclude one or more buses connected to each other through variousbridges, controllers, and/or adapters, as is well-known in the art. Inone embodiment, the I/O controller 1009 includes a USB (Universal SerialBus) adapter for controlling USB peripherals. Alternatively, I/Ocontroller 1009 may include an IEEE-1394 adapter, also known as FireWireadapter, for controlling FireWire devices.

Thus, techniques for providing multi-radio wireless mesh networksolutions have been described herein. Some portions of the precedingdetailed descriptions have been presented in terms of algorithms andsymbolic representations of operations on data bits within a computermemory. These algorithmic descriptions and representations are the waysused by those skilled in the data processing arts to most effectivelyconvey the substance of their work to others skilled in the art. Analgorithm is here, and generally, conceived to be a self-consistentsequence of operations leading to a desired result. The operations arethose requiring physical manipulations of physical quantities. Usually,though not necessarily, these quantities take the form of electrical ormagnetic signals capable of being stored, transferred, combined,compared, and otherwise manipulated. It has proven convenient at times,principally for reasons of common usage, to refer to these signals asbits, values, elements, symbols, characters, terms, numbers, or thelike.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. Unlessspecifically stated otherwise as apparent from the above discussion, itis appreciated that throughout the description, discussions utilizingterms such as “processing” or “computing” or “calculating” or“determining” or “displaying” or the like, refer to the action andprocesses of a computer system, or similar electronic computing device,that manipulates and transforms data represented as physical(electronic) quantities within the computer system's registers andmemories into other data similarly represented as physical quantitieswithin the computer system memories or registers or other suchinformation storage, transmission or display devices.

Embodiments of the present invention also relate to an apparatus forperforming the operations herein. This apparatus may be speciallyconstructed for the required purposes, or it may comprise ageneral-purpose computer selectively activated or reconfigured by acomputer program stored in the computer. Such a computer program may bestored in a computer readable storage medium, such as, but is notlimited to, any type of disk including floppy disks, optical disks,CD-ROMs, and magnetic-optical disks, read-only memories (ROMs), randomaccess memories (RAMs), erasable programmable ROMs (EPROMs),electrically erasable programmable ROMs (EEPROMs), magnetic or opticalcards, or any type of media suitable for storing electronicinstructions, and each coupled to a computer system bus.

The algorithms and displays presented herein are not inherently relatedto any particular computer or other apparatus. Various general-purposesystems may be used with programs in accordance with the teachingsherein, or it may prove convenient to construct more specializedapparatus to perform the required method operations. The requiredstructure for a variety of these systems will appear from thedescription below. In addition, embodiments of the present invention arenot described with reference to any particular programming language. Itwill be appreciated that a variety of programming languages may be usedto implement the teachings of embodiments of the invention as describedherein.

A machine-readable medium may include any mechanism for storing ortransmitting information in a form readable by a machine (e.g., acomputer). For example, a machine-readable medium includes read onlymemory (“ROM”); random access memory (“RAM”); magnetic disk storagemedia; optical storage media; flash memory devices; etc.

In the foregoing specification, embodiments of the invention have beendescribed with reference to specific exemplary embodiments thereof. Itwill be evident that various modifications may be made thereto withoutdeparting from the broader spirit and scope of the invention as setforth in the following claims. The specification and drawings are,accordingly, to be regarded in an illustrative sense rather than arestrictive sense.

1. A machine-implemented method for configuring wireless mesh accesspoints of a wireless mesh network, the method comprising: monitoring bymonitoring logic, via a dedicated monitoring antenna of a current meshaccess point (AP), routing information of a plurality of neighboringmesh APs, the current mesh AP being one of a plurality mesh APs of awireless mesh network, wherein each of the mesh APs includes an uplinkantenna to communicate with an uplink mesh AP, a downlink antenna tocommunicate with a downlink mesh AP, a local link antenna to communicatewith a local client of each mesh AP, and a monitoring antenna formonitoring neighboring mesh APs; and dynamically reconfiguring andrerouting traffic of an uplink antenna of the wireless mesh AP from afirst routing path coupled to a first uplink mesh AP to a second routingpath coupled to a second uplink mesh AP, if the second routing path hasa better routing condition than the first routing path based on themonitored routing information associated with the first uplink mesh APand the second uplink mesh AP obtained via the dedicated monitoringantenna of the mesh AP.
 2. The method of claim 1, wherein the monitoredrouting information of an AP comprises a hop count to reach a destinednode via the AP and signal strength of the AP.
 3. The method of claim 1,further comprising: monitoring, via the dedicated monitoring antenna,traffic conditions of channels used by neighboring mesh APs, includingan existing channel used by a downlink antenna and a local link antennaof the current mesh AP; and dynamically assigning a new channel to adownlink interface associated with the downlink antenna of the currentmesh AP if congestion of the existing channel used by the downlinkinterface of the current mesh AP reaches a predetermined threshold basedon the monitored traffic conditions.
 4. The method of claim 3, furthercomprising dynamically assigning a new channel to a local link interfaceassociated with the local link antenna of the current mesh AP ifcongestion of the existing channel used by the local link interface ofthe current mesh AP reaches a predetermined threshold based on themonitored traffic conditions.
 5. The method of claim 4, wherein thetraffic condition of a channel is determined based on a number ofdownlink mesh APs currently associated with the channel and asignal-to-noise ration (SNR) of the channel.
 6. The method of claim 4,further comprising: transmitting via the dedicated monitoring antenna aquery message to a specific neighboring mesh AP to request the specificneighboring mesh AP to identify itself; in response to receiving aresponse from the specific neighboring mesh AP, examining the responseto determine whether the response contains a predetermined signatureassociated with the mesh network; and alerting a management system ofthe mesh network if the response does not contain a predeterminedsignature associated with the mesh network.
 7. A machine-readablestorage medium having instructions stored therein, which when executedby a processor, cause the process to perform a method for configuringwireless mesh access points of a wireless mesh network, the methodcomprising: monitoring by monitoring logic, via a dedicated monitoringantenna of a current mesh access point (AP), routing information of aplurality of neighboring mesh APs, the current mesh AP being one of aplurality mesh APs of a wireless mesh network, wherein each of the meshAPs includes an uplink antenna to communicate with an uplink mesh AP, adownlink antenna to communicate with a downlink mesh AP, a local linkantenna to communicate with a local client of each mesh AP, and amonitoring antenna for monitoring neighboring mesh APs; and dynamicallyreconfiguring and rerouting traffic of an uplink antenna of the wirelessmesh AP from a first routing path coupled to a first uplink mesh AP to asecond routing path coupled to a second uplink mesh AP, if the secondrouting path has a better routing condition than the first routing pathbased on the monitored routing information associated with the firstuplink mesh AP and the second uplink mesh AP obtained via the dedicatedmonitoring antenna of the mesh AP.
 8. The machine-readable storagemedium of claim 7, wherein the monitored routing information of an APcomprises a hop count to reach a destined node via the AP and signalstrength of the AP.
 9. The machine-readable storage medium of claim 7,wherein the method further comprises: monitoring, via the dedicatedmonitoring antenna, traffic conditions of channels used by neighboringmesh APs, including an existing channel used by a downlink antenna and alocal link antenna of the current mesh AP; and dynamically assigning anew channel to a downlink interface associated with the downlink antennaof the current mesh AP if congestion of the existing channel used by thedownlink interface of the current mesh AP reaches a predeterminedthreshold based on the monitored traffic conditions.
 10. Themachine-readable storage medium of claim 9, wherein the method furthercomprises dynamically assigning a new channel to a local link interfaceassociated with the local link antenna of the current mesh AP ifcongestion of the existing channel used by the local link interface ofthe current mesh AP reaches a predetermined threshold based on themonitored traffic conditions.
 11. The machine-readable storage medium ofclaim 10, wherein the traffic condition of a channel is determined basedon a number of downlink mesh APs currently associated with the channeland a signal-to-noise ration (SNR) of the channel.
 12. Themachine-readable storage medium of claim 10, wherein the method furthercomprises: transmitting via the dedicated monitoring antenna a querymessage to a specific neighboring mesh AP to request the specificneighboring mesh AP to identify itself; in response to receiving aresponse from the specific neighboring mesh AP, examining the responseto determine whether the response contains a predetermined signatureassociated with the mesh network; and alerting a management system ofthe mesh network if the response does not contain a predeterminedsignature associated with the mesh network.
 13. A wireless mesh accesspoint (AP), comprising: an uplink interface to wirelessly communicatewith an uplink mesh AP; a downlink interface to wirelessly communicatewith one or more downlink mesh AP; a local link interface to wirelesslycommunicate with one or more local clients; a monitoring interface; amonitoring logic configured to, via a monitoring interface, routinginformation of a plurality of neighboring mesh APs associated with awireless mesh network, wherein each of the mesh APs includes an uplinkantenna to communicate with an uplink mesh AP, a downlink antenna tocommunicate with a downlink mesh AP, a local link antenna to communicatewith a local client of each mesh AP, and a monitoring antenna formonitoring neighboring mesh APs; and a routing logic configured todynamically reconfigure and reroute traffic of the uplink interface ofthe wireless mesh AP from a first routing path coupled to a first uplinkmesh AP to a second routing path coupled to a second uplink mesh AP, ifthe second routing path has a better routing condition than the firstrouting path based on the monitored routing information associated withthe first uplink mesh AP and the second uplink mesh AP obtained via themonitoring interface of the mesh AP.
 14. The wireless mesh AP of claim13, wherein the monitored routing information of an AP comprises a hopcount to reach a destined node via the AP and signal strength of the AP.15. The wireless mesh AP of claim 14, wherein the monitoring logic, viathe monitoring interface, is configured to monitor traffic conditions ofchannels used by neighboring mesh APs, including an existing channelused by the downlink interface and the local link interface of the meshAP, and wherein the routing logic is configured to dynamically assign anew channel to the downlink interface of the mesh AP if congestion ofthe existing channel used by the downlink interface reaches apredetermined threshold based on the monitored traffic conditions. 16.The wireless mesh AP of claim 15, wherein the routing logic furtherdynamically assigns a new channel to the local link interface of themesh AP if congestion of the existing channel used by the local linkinterface reaches a predetermined threshold based on the monitoredtraffic conditions.
 17. The wireless mesh AP of claim 16, wherein thetraffic condition of a channel is determined based on a number ofdownlink mesh APs currently associated with the channel and asignal-to-noise ration (SNR) of the channel.
 18. The wireless mesh AP17, wherein the monitoring logic is further configured to transmit viathe monitoring interface a query message to a specific neighboring meshAP to request the specific neighboring mesh AP to identify itself, inresponse to receiving a response from the specific neighboring mesh AP,examine the response to determine whether the response contains apredetermined signature associated with the mesh network, and alert amanagement system of the mesh network if the response does not contain apredetermined signature associated with the mesh network.